(OMIM 611773)

Acronym for Hereditary Angiopathy with Nephropathy, Aneurysms and muscular Cramps. 

This is one of the genetic causes of stroke. Autosomal dominant transmission of mutations of the COL4A1 or COL4A2 gene causing anomalies of strings alpha 3, 4 and 5 of collagen IV, a major component of all basal membranes ("basalopathy"). These changes concern mainly the vascular basement membranes. The phenotypic expression is highly variable with stroke, retinal, renal and muscular involvement:

-         cerebral microangiopathy with leucopathy; small intracranial aneurysms

-         tortuosity of retinal arteries which can result in recurrent retinal hemorrhages

-         micro-ou macroscopic hematuria. Renal cysts; moderate renal failure (hematuria)

-         muscle cramps from the early years of life; myalgia; moderately elevated CPK level (2 to 3 x normal).

Sometimes: Raynaud's syndrome, supraventricular arrhythmia.

Anesthetic implications: 

monitor renal function; avoid hypertensive peaks (intubation) and intraoperative hyperventilation

References : 

-        Plaisier E, Gribouval O, Alamovitch S, Mougenot B et al. 
COL4A1 mutations and hereditary angiopathy, nephropathy, aneurysms, and muscle cramps. 
N Engl J Med 2007; 357: 2687-95.

-        Salomon R. 
Syndromes avec anomalies rénales in 
Progrès en Pédiatrie : syndromes dysmorphiques par Lacombe D et Philip N, Doin 2013, p 139-50

Updated: April 2019